Although the relation between time and frequency is reciprocal, I guess there will be some more complex issues with respect to ADC as it follows different architectures and methods to convert that "analog voltage level" to its "digital equivalent. For Flash ADC the relation is simple as discussed. For pipelined ADC, you get the output after certain delay called as latency. For SAR again the output pattern will be different.
In my opinion clock rate of the ADC could be taken as more un-ambiguous term.